Louis D

My favorite quote of the entire article:

you don’t need 8-12” to have fun!

4” or 5” is enough to keep you busy for decades!

56 minutes ago, glafnazur said:

The paragraph below interested me. I used to do this and then read that quite a few people leave the lens cap off so I started doing that, maybe I'll go back to cap on.

When bringing from a cold environment to a warm environment, put lens caps on for the scope and eyepieces, and put them in their case if possible. Close the case to trap in the cold air, then bring the cases inside and let them slowly warm up over 12-24 hours. This is to prevent frost from forming on a lens surface (even on the inside of the tube

If I'm bringing my gear in from a hot, steamy environment to a drier, air conditioned environment; then yes, I do keep everything uncapped to let the excess moisture escape and recap everything later in the night or in the morning.  However, the above is what I've always done in the winter.  Otherwise, you'll end up with condensation on everything and you have to wait to put everything away just like in the summer.

23 hours ago, Higgs_Bozon said:

The best focus has a point in the middle and a spill on the top right, like paint spilling.

Is the light spill mostly violet?  If so, that is completely normal for a fast achromat like yours.  Try a #8 Yellow filter to tame it down a bit.

Try focusing with a #56 Green filter to see if the star images are sharper.  Correction at the red end of the spectrum might be as bad as at the blue end with your scope.  The green filter will cut out both and will probably show a sharper image.  I'm not saying it will be a pleasing image, but we'll start to narrow down the problem source.

Yep, a pretty good and well organized summary of discussions on the various refractor forums.

He does completely ignore high quality, slow achromats like those that were made by D&G Optical.  Admittedly, they're only available on the secondary market now.

I'd probably suggest you start out spending a fraction of the $2000 budget on a good starter scope that is still compact.  If you find you're not that into astronomy later, you can easily pass it along.

I would suggest either a Sky-Watcher Heritage 130 or 150, but mounted alt-az style on a photographic ballhead on a sturdy tripod:

Or on a Sky-Watcher AZ5 mount:

If you prefer a driven mount, they can also be had on a goto mount in the Virtuoso GTi 150P version which can be mounted on a photographic tripod:

We have millions of Mexican free-tailed bats around here.  They help contain the insect population in the summer.

Just don't go below the bridges where they roost when they're flying out at twilight unless you like bat guano on your head. 

On 02/11/2023 at 05:54, Mr Spock said:

(I like to be seated). It's gone back to FLO for adjustment 

You sent your derriere to FLO for adjustment?  Perhaps try a chiropractor next time. 😏😁

Also, if using a traditional long Barlow, be careful when inserting it into the rear port to avoid hitting the corrector lens if indeed it is at the back of the scope and not on the secondary.

17 hours ago, Mr Spock said:

I can't access next door's drain as there's a wall in between properties. As next door is much lower than here the rainwater must be going there somehow as there's nowhere else it could go.

It boggles the mind that the builder was allowed to block the natural drainage by building that wall.  I forced my neighbor to remove foot high metal edging along his side of our common privacy fence that was causing water to pool 6 inches deep on my side (the high side).  I pointed out that Texas law forbids blocking the natural drainage of water causing adjacent properties to flood.

The section of Texas code:

Texas Water Code 11.086:

(a) No person may divert or impound the natural flow of surface waters in this state, or permit a diversion or impounding by him to continue, in a manner that damages the property of another by the overflow of the water diverted or impounded.

You might want to check on your local water code laws to see if you can force a drainage notch to be cut into the bottom of that common wall.

What about getting a 20mm 100 degree eyepiece instead of the ES 24mm 82 degree?  It should have similar TFOV and eye relief but at a slightly higher magnification.  The various Lunt/APM HW rebrandings here in the US tend to be cheaper than the similar focal length ES 82 degree offerings.

By the looks of it, you have a mostly level area with poor or even blocked drainage.  You'll need to figure out where that water would normally drain to.  Then, you might need to investigate putting in a French drain to channel the water to that natural drain.  My niece had to do that with her backyard because it was a basin with nowhere for the water to go.  Putting in the drain involved digging a 70 foot long trench from the center of the backyard, along the side of her house, to the street, for the drainage pipe.

Around the US, you must call 811 to have gas and other utility providers come out for free to mark their buried lines before you dig.  Doesn't the UK have a similar service/requirement?

You would need to replace the entire finder scope with a RACI (Right Angle Correct Image) finder scope.  To fit a diagonal to the back end of one would necessitate cutting down the tube length to account for the additional optical path length of the diagonal.

On 29/10/2023 at 17:40, The60mmKid said:

I once bought a pair of binocular glasses because a questionable seller on CloudyNights claimed they had "sharp optics." Har har. The despicable little thing was so flimsy and impossible to align that it would immediately cause a headache and nausea when you put it on. And to rub it in further, it would pinch your nose with its sharp edges... Proof that evil exists!

That reminds of the build it yourself equatorial platform kit I bought back in the late 90s.  The problem was that it used friction sliders at an angle on the tracking board, so it could never track smoothly.  I tried substituting various wheels, but could never make it work satisfactorily.  Over $250 in 1990s dollars down the drain.

3 hours ago, Simone_DB said:

And since we're here I have a question that I didn't see addressed on my manuals: is there a specific initial orientation of the tube (ocular/finder scope wise), say when the scope is in the "home" position, to allieviate the comfort issue? Or does the ocular may end up in any position so that there's no a sensible answer to that? I hope that makes sense.

We'd kind of need to know which type of telescope you have to answer this.  I suspect you have a Newtonian with the focuser sticking out of the tube near the top.  The eyepiece will end up pointing in all sorts of weird directions depending on where the scope is pointed when mounted on an EQ mount.  If this is the case, you can put a large hose (jubilee?) clamp or embroidery ring or similar ring around the tube just above the upper tube ring and then loosen the tube rings just enough to allow it to be rotated with a slight bit of effort.  The extra ring keeps the tube from sliding out of the main rings when loosened.  You may want to put some non-marring material between the tube and clamp/ring.

If you've got a refractor, SCT, or Mak, just rotate the diagonal to the most comfortable viewing position.

You learned that an alt-az mount is a much better choice for a grab and go setup.  That, and having your scope setup at the right height to enable sitting while observing is essential to avoiding backaches.

Most in the US use 1/4-20 threading.  You'll want hex socket cap head screws regardless of thread size.

It takes a lot of crud on an objective to become noticeable.  This is nowhere close to that level.

4 hours ago, Don Pensack said:

Though it kind of makes the wives depart quickly from the room.

Sounds good to me! 😄

The 31mm Nagler T5 might be another option to replace the 32mm Panaview SWA if you like 82 degree eyepieces.

The Nikon NAV-HW 12.5mm and 17mm eyepieces are another premium hyperwide option.  Each comes with a dedicated screw on optical element to allow the 17mm to become a 14mm eyepiece and the 12.5mm to become a 10mm eyepiece with no optical quality loss.  Most reviewers indicate they slightly edge out the Ethos and have more comfortable eye relief.  The 17mm can be difficult to achieve perfect coma correction in a Paracorr II, though.

21 hours ago, Shimrod said:

There is a compatible one on Amazon for $17 that seems to have a reasonable number of positive reviews - https://www.amazon.com/Compatible-Celestron-Telescope-Replacement-switching/dp/B00DILJCZM

Looks a lot like the ebay ones I was referencing.

2 hours ago, Naughty Neal said:

The jack plug is a common one used 5.5mm x 2.1mm so any power supply of the correct voltage and amperage  will work. 

Brand name pricing = kerching , it isn't only Celestron but all brands in any type of market does it.

My point exactly.

I've found power supplies are much simpler to replace than obsolete laptop batteries.  Most of the generic replacement batteries don't have the necessary electronics built into to them to take a charge.

34 minutes ago, jjohnson3803 said:

I had a RACI finder where the lock (inner) ring didn't screw down quite far enough to bring the finder into perfect focus.  I think the threads were cut a small bit too short or my eyeglasses prescription was a bit off.

Anyway, I just removed the lock ring and focused the objective without locking it down.  The downside is you'll have to refocus if the objective rotates at all, but it wasn't necessary to do that  very often.

You might be able to find a step ring threaded all the way through that would be much thinner than the original lock ring.  I just have no idea what thread size it's using.

I'm no imager, but I use a TSFLAT2 on my 72ED and 90mm APO refractors to good effect.  I can't stand field curvature with ultrawide eyepieces and low powers.

I attach it to the front of my diagonal, replacing the 2" diagonal's nosepiece.  I use 15mm of spacer extension for best correction visually.

6 hours ago, Ags said:

Sounds like my kind of party. You're both invited!

Me too.  Nothing wrong with such talk when everyone in the room is an astro geek.

1 minute ago, John said:

At what exit pupil does the secondary shadow start to show with an SCT ?

I haven't tried it with an SCT, but in my f/6 and faster Newts, I start noticing secondary shadow on the moon and sun at around 5mm to 6mm exit pupil.  It's quite strong by 8mm.  When fully dark adapted and looking at DSOs, I can't recall ever seeing secondary shadow at any exit pupil.

Getting to a large exit pupil at f/10 in an SCT is much more difficult than at f/5 in a Newt.  Perhaps with the SCT + F/R operating at f/6.3 it would be more of an issue.